The present invention relates generally to phosphoinositides which have demonstrated antibacterial activity and particularly to phosphoinositides which can be used for the prophylaxis and treatment of bacterial infections and particularly for the prophylaxis and treatment of bacterial infections caused by Haemophilus influenzae. 
In the United States, otitis media, next to upper respiratory tract infections, is the most common cause for outpatient visits to pediatricians. Fifteen to twenty per cent of children younger than six years of age contract otitis media. Otitis media is an inflammation of the middle ear characterized by symptoms such as otalgia, hearing loss and fever. One of the primary causes of these symptoms is a build up of fluid (effusion) in the middle ear. Complications include permanent hearing loss, perforation of the tympanic membrane, acquired cholesteatoma, mastoiditis, and adhesive otitis. Children who develop otitis media in the first years of life are at risk for recurrent acute or chronic disease.
One of the primary causes of otitis media is Haemophilus influenzae, which is commonly known as xe2x80x9cH. influenzae.xe2x80x9d It is thought that H. influenzae causes otitis media by adhering to nasopharyngeal cells. The adherence of H. influenzae to nasopharyngeal cells causes those cells to become infected and to produce secretions. The middle ear becomes infected because mechanical or functional obstruction of the Eustachian tube, which protects the middle ear from nasopharyngeal secretions, results in negative middle ear pressure. This negative pressure causes the nasopharyngeal secretions to enter the middle ear resulting in an infection, such as otitis media, usually with effusion.
Typically, otitis media is treated by means of administering a course of antibiotics consisting of a penicillin derivative. Other supportive therapies, such as analgesics, antipyretics and local heat are also helpful. Often, surgery is required to remove fluid from the middle ear and to relieve the pain experienced by the child.
Currently, no reliable prophylactic treatments are known. It has been demonstrated that human casein inhibits the adhesion of H. influenzae to human respiratory tract epithelial cells. See Aniansson, et. al., Microbial Pathogenesis 1990;8:315-323. Aniansson, et al., found that human casein represents a new mechanism for the protection by breast-milk against respiratory tract infection. Thus, it is thought that human casein may be effective as a prophylactic treatment for otitis media but further study is required.
Polyphosphoinositides have been reported to be present in inner ear and kidney tissue. See U.S. Pat. No. 4,897,384 to Janoff, et al. Phosphatidylinositol diphosphate has been postulated to serve as an in vivo receptor for aminoglycoside antibiotics. See Lodhi, et al., Biochem. Pharmacol. 29:597-601 (1990). Dipalmitoylphosphatidylinositol-3,4-diphosphate ammonium salt (PI-3,4-PP) is known to be a membrane lipid present in human erthyrocytes. However, no anti-bacterial activity of polyphosphoinositides has been previously reported.
For these reasons, a need still exists in the art for a composition and method for the prophylaxis and treatment of infections caused by Haemophilus influenzae and its clinical manifestations, such as, for example, otitis media.
It has been discovered that certain phosphoinositides demonstrate antibacterial activity. Particularly, these phosphoinositides have been discovered to prevent the adhesion of H. influenzae onto the nasopharyngeal cells of mammals, and, in particular, humans. Phosphoinositides useful with the present invention have the following formula (1): 
wherein R1 and R2 are selected from the group consisting of hydrogen and monounsaturated and saturated fatty acids having a carbon chain length of C6 to C20 and R2 and R1 can be the same or different; and R3 to R7 are selected from the group consisting of hydrogen or a phosphate moiety with at least two of R3 to R7 being a phosphate moiety; and hydrates and pharmaceutically acceptable salts thereof.
One aspect of the present invention is directed to a nutritional formulation for the prophylaxis and treatment of Haemophilus influenzae infection and its clinical manifestations comprising an effective amount of a compound of the formula (1). Another aspect of the present invention is directed to a pharmaceutical composition for the prophylaxis and treatment of Haemophilus influenzae infection and its clinical manifestations comprising an effective amount of a compound of the formula (1). Still another aspect of the present invention is directed to a method for the prophylaxis and treatment of bacterial infections comprising administering to a patient an effective amount of a compound of the formula (1). Yet another aspect of the present invention is directed to a method for the prophylaxis and treatment of otitis media comprising administering to a patient an effective amount of a compound of the formula (1).
In the above aspects of the invention, R1 and R2 are desirably both fatty acids; R1 is desirably a fatty acid and R2 is desirably hydrogen; or R1 and R2 are both desirably hydrogen.
If R1 and R2 are both fatty acids, then R3, R6 and R7 are desirably hydrogen and at least one of R4 and R5 is desirably a phosphate moiety. More desirably, the compound is selected from the group consisting of diacylphosphatidylinositol-3-monophosphate, diacylphosphatidylinositol4-monophosphate and diacylphosphatidylinositol-3,4-diphosphate. Most desirably, the compound is dipalmitoylphosphatidylinositol-3,4-diphosphate.
If R1 is a fatty acid and R2 is hydrogen, then R3, R6 and R7 are desirably hydrogen and at least one of R4 and R5 is desirably a phosphate moiety. More desirably, the compound is selected from the group consisting 1-monoacylphosphatidylinositol-3-monophosphate, 1-monoacylphosphatidylinositol-4-monophosphate and 1-monoacylphosphatidylinositol-3,4-diphosphate.
If R1 and R2 are both hydrogen, then R3, R6 and R7 are desirably hydrogen and at least one of R4 and R5 is desirably a phosphate moiety. More desirably, the compound is selected from the group consisting of 3-phosphoglyceroinositol-3-monophosphate, 3-phosphoglyceroinositol4-monophosphate and 3-phosphoglyceroinositol-3,4-diphosphate.
Other objects and advantages of the invention will be apparent from the following detailed description and the appended claims.
As stated above, it has been discovered that certain phosphoinositides demonstrate antibacterial activity. Particularly, these phosphoinositides have been discovered to prevent the adhesion of H. influenzae onto the nasopharyngeal cells of mammals, and, in particular, humans. Phosphoinositides useful with the present invention have the following formula (1): 
wherein R1 and R2 are selected from the group consisting of hydrogen and monounsaturated and saturated fatty acids having a carbon chain length of C6 to C20 and R3 and R2 can be the same or different; and R3to R7 are selected from the group consisting of hydrogen or a phosphate moiety with at least two of R3to R7 being a phosphate moiety; and hydrates and pharmaceutically acceptable salts thereof.
In the above compound, R1 and R2 are desirably both fatty acids; R1 is desirably a fatty acid and R2 is desirably hydrogen; or R1 and R2 are both desirably hydrogen.
If R1 and R2 are both fatty acids, then R3, R6 and R7 are desirably hydrogen and at least one of R4 and R5 is desirably a phosphate moiety. More desirably, the compound is selected from the group consisting of diacylphosphatidylinositol-3-monophosphate, diacylphosphatidylinositol-4-monophosphate and diacylphosphatidylinositol-3,4-diphosphate. Most desirably, the compound is dipalmitoylphosphatidylinositol-3,4-diphosphate.
If R1 is a fatty acid and R2 is hydrogen, then R3, R6 and R7 are desirably hydrogen and at least one of R4 and R5 is desirably a phosphate moiety. More desirably, the compound is selected from the group consisting of 1-monoacylphosphatidylinositol-3-monophosphate, 1-monoacylphosphatidylinositol-4-monophosphate and 1-monoacylphosphatidylinositol-3,4-diphosphate.
If R1 and R2 are both hydrogen, then R3, R6 and R7 are desirably hydrogen and at least one of R4 and R5 is desirably a phosphate moiety. More desirably, the compound is selected from the group consisting of 3-phosphoglyceroinositol-3-monophosphate, 3-phosphoglyceroinositol-4-monophosphate and 3-phosphoglyceroinositol-3,4-diphosphate.
Most of the compounds which are useful with this invention are commercially available from Matreya, Inc. of Pleasant Gap, Pa. Other compounds of this invention can be formed by linking together two commercially available precursors. Particularly, most of the useful compounds can be synthesized by linking 3-phosphoglycerol with phytate and then subsequently modifying the resulting chemical structure to produce the desired compound. For example, the glycerol portion of the chemical structure can be esterified to appropriate fatty acids. As another example, the phytate portion of the chemical structure can be partially dephosphorylated to remove the desired number of phosphate groups from that portion of the chemical structure, Both 3-phosphoglycerol and phytate are commercially available from Matreya, Inc.
Phosphatidylinositol-3,4-diphosphate can also be synthesized by phosphorylating phosphatidylinositol or phosphatidylinositol-4-phosphate at the 3 position on the inositol ring with phosphatidylinositol-3-kinase. Phosphatidylinositol-3,4-diphosphate may also be produced by phosphorylation at the 4 position on the inositol ring of phophatidylinositol-3-phosphate with phosphatidylinositol-4-kinase.